Auditory Discrimination

We do not hear by our ears but by our brains.

Auditory discrimination is most important, when trying to learn to read. To differentiate
between knowledge of words and language-free discrimination, 4 tasks were designed, that
could not be solved by the sense organs but did not rely on language processing. All tasks
were of the type "two alternative forced choice".

Age development

Using the tasks in subjects of different ages between 7 and 70 years yielded improvements
until the age of 18 - 20 years (adult age). Above the age of 35 years thresholds begin to
increase especially those of frequency discrimination and time order.

Auditory Discrimination in Dyslexia

Using the tasks in subjects with dyslexia showed deficits of different strength depending on
age and tasks. Frequency discrimination and time order were affected most strongly. The age
curves of time order can be seen in the figure.

The percentages of affected subjects vary between 60 and 70% as can be seen in the right
panel.

Auditory Training and Transfer to Spelling

Daily practice at home using FonoTrain yielded significant improvements in auditory
discrimination. The figure shows the percent number of subjects, who performed below the 16
percentile before the raining and reached the 20% (or better) after the training.

While 3 of the 4 tasks were learned by 60% or more of the participants, time order was more
difficult to learn. But once the training was successful the mean value of the percentiles were
60 to 70 including time order (see left panel). This shows that on average the subjects
performed better than the controls. Surprisingly enough, the training lasts no longer than 10
days for each auditory domain.

When spelling tests were given before and after the training the relative reduction of spelling
errors was 40% for the training subjects and 12% for the control subjects (see right panel). A
placebo effect was not observed.